How common is Niemann-Pick type C disease?

Niemann-Pick type C disease (NP-C) is an extremely rare disorder that can affect infants, children and adults up to, and even over, 50 years old.^1,2 Current estimates suggest that NP-C is seen in about one in every 150,000 people in Europe with a similar rate across the world.¹ It is likely, however, that the incidence of NP-C has probably been underestimated, owing to its varied clinical symptoms and difficulties in diagnosis, particularly in the very young when the condition is often devastating.¹

References

1. Wraith JE, Imrie J. Understanding Niemann-Pick disease type C and its potential treatment. UK Blackwell Publishing, 2007.
2. Sévin M, Lesca G, Baumann N et al. The adult form of Niemann–Pick disease type C. Brain 2006;130:120–33.